Benzimidazole compounds are gathering much attention as therapeutic agents for peptic ulcer and/or prophylactic agents for relapse of ulcer, because they have gastric acid antisecretory and gastric mucosa-protecting activities.
As compositions for rectal administration of such benzimidazole compounds, there has been reported 1) a rectal suppository comprising (i) omeprazole, (ii) a mixture of polyethylene glycols or a mixture of adeps solidus and sodium laurylsulfate and (iii) a water-soluble basic amino acid (U.S. Pat No. 5,219,870), 2) a form of suppositories comprising an omeprazole compound and a neutral fat base (U.S. Pat. No. 4,738,974), and 3) a suppository comprising (i) a 2-[(2-pyridyl)methylsulfinyl]benzimidazole compound having antiulcer activity and (ii) hard fat whose acid value is less than 13 and hydroxy group value is less than 40 (JP-A-5213752), but neither of them is fully satisfactory in the stability of the active ingredient in the composition. A gastrointestinal mucosa-adherent matrix is reported (EP-A-514008), but no rectal dosage composition comprising such mucosa-adherent matrix is known.